I'm translating this at Google Translation, so sorry if it's strange English.
It looked interesting, so I tried it with a Champion Target Golem-Tower Lord to see if I could get 4k with Axe's auto attack.
In the case of this golem, 4k seems to be possible with 3400+ power and 300+ ferocity under the following conditions.
Superior Rune of the Scholar : +5%damage
Superior Sigil of Force : +5%damage
Hunter's Tactics : +10%damage
Furious Strength : +7%damage
Twice as Vicious : +5%damage
Oppressive Superiority : +10%damage
In addition, if you use "Sic 'Em", you can hope to get 5k.
I'll upload a video of just punching the golem along with it.